Class: Melbourne::AST::FormalArguments

Inherits:
Node
  • Object
show all
Defined in:
lib/melbourne/ast/definitions.rb

Overview

The formal arguments of a method definition as in:

def method(x) # x is a formal argument of the method
end

Instance Attribute Summary collapse

Attributes inherited from Node

#line

Instance Method Summary collapse

Methods inherited from Node

#ascii_graph

Constructor Details

#initialize(line, args, defaults, splat) ⇒ FormalArguments

Returns a new instance of FormalArguments.



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# File 'lib/melbourne/ast/definitions.rb', line 178

def initialize(line, args, defaults, splat)
  @line = line
  @defaults = nil
  @block_arg = nil

  if defaults
    defaults = DefaultArguments.new line, defaults
    @defaults = defaults
    @optional = defaults.names

    stop = defaults.names.first
    last = args.each_with_index { |a, i| break i if a == stop }
    @required = args[0, last]
  else
    @required = args.dup
    @optional = []
  end

  if splat.kind_of? Symbol
    args << splat
  elsif splat
    splat = :@unnamed_splat
    args << splat
  end
  @names = args
  @splat = splat
end

Instance Attribute Details

#block_arg ⇒ Object

The block argument if there is one



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# File 'lib/melbourne/ast/definitions.rb', line 176

def block_arg
  @block_arg
end

#defaults ⇒ Object

The arguments of the method that have default values



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# File 'lib/melbourne/ast/definitions.rb', line 168

def defaults
  @defaults
end

#names ⇒ Object

The names of the arguments



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# File 'lib/melbourne/ast/definitions.rb', line 156

def names
  @names
end

#optional ⇒ Object

The names of the optional arguments



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# File 'lib/melbourne/ast/definitions.rb', line 164

def optional
  @optional
end

#required ⇒ Object

The names of the required arguments



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# File 'lib/melbourne/ast/definitions.rb', line 160

def required
  @required
end

#splat ⇒ Object

The splat (+*some+) arguments of the method



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# File 'lib/melbourne/ast/definitions.rb', line 172

def splat
  @splat
end

Instance Method Details

#arity ⇒ Object

Gets the arity of the method. The arity is the number of required arguments the method defines.

Example

def method(a, b = 1) # arity is 1 as the second argument is optional
end



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# File 'lib/melbourne/ast/definitions.rb', line 218

def arity
  @required.size
end

#required_args ⇒ Object

Gets the number of required arguments the method defines.



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# File 'lib/melbourne/ast/definitions.rb', line 224

def required_args
  @required.size
end

#splat_index ⇒ Object

TODO: document!



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# File 'lib/melbourne/ast/definitions.rb', line 235

def splat_index
  if @splat
    index = @names.size
    index -= 1 if @block_arg
    index -= 1 if @splat.kind_of? Symbol
    index
  end
end

#total_args ⇒ Object

Gets the total number of all arguments the method defines.



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# File 'lib/melbourne/ast/definitions.rb', line 230

def total_args
  @required.size + @optional.size
end